The war in Ukraine is a never-ending catastrophe. Russian forces, concentrated in the east, continue to inflict terrible damage on Ukrainian soldiers and civilians alike. Countless lives have been lost and upended. Once again, the world must confront the possibility of nuclear war and grapple with a compounding refugee and cost of living crisis. This isn’t the “end of history” that we hoped for.Less violently, another transformation is taking place: After three decades of exchange, interaction and engagement, the door between Russia and America is slamming shut. Practically every day another American company — including the most symbolic of them all, McDonald’s, whose golden arches heralded a new era 30 years ago — pulls out of Russia. Diplomats have been expelled, concerts canceled, products withdrawn, personal visits called off. In the shuttered consulates, nobody is issuing visas, and even if they were, American airspace is now closed to Russian aircraft. The only substantive interaction left seems to be the issuing of sanctions and counter-sanctions.For a Russian American like me, whose life has been forged in the interstices between the two cultures, it’s a bewildering, sorrowful turn of events. Measures to curtail the Kremlin’s capacity of aggression are, to be clear, politically and morally necessary. But the collateral damage is a severing of ties that is bound to revive harmful stereotypes and close down the space for cross-cultural pollination. More profoundly, the current parting of ways marks the definitive end of a period when Russia’s integration with the West, however vexed, appeared possible — and the antagonism between ideological superpowers was a thing of the past.That’s certainly how it felt on a warm March day in 1989 in Krasnodar, the provincial southern town near the Black Sea where I grew up. My school was hosting a group of seniors from a high school in New Hampshire: I was about to turn 17, and until that day America existed in my mind only as an abstract concept. It was the villain of a New Year’s holiday show, the object of Nikita Khrushchev’s quest “To catch up and overtake America” and home to the “Star Wars” program — just one, we were told, of the imperialists’ many designs to take down the Soviet Union.Only those boys and girls in jeans and sweatshirts who appeared in our schoolyard didn’t look like imperialists, or appear to be threatening at all. They looked like better-dressed versions of us: shy, well-meaning and fascinated. Just a few hours ago, during our military training class, we had been assembling Kalashnikov guns to be used on enemy agents. And here they were, standing in front of us. We stared at each other. Then someone smiled, someone said hello. In a matter of minutes, the wariness between us was gone. “I’m reading ‘Crime and Punishment’ for spring break,’” a tall guy with a silver earring told me. “Raskolnikov is cool!”Over the next five days of mutual discovery, we learned that the Americans were also afraid of nuclear war, only in their version, it would be waged by us. That when transcribed, the lyrics of “Ice Ice Baby” didn’t make much sense. That “pot” had a meaning other than a kitchen item, as explained by the Raskolnikov fan. And that when a boy tells a girl that she’s “special,” that’s, well, special. Together we roamed the streets, snapping photos next to Lenin statues — or rather, as the Americans put it, we “hung out.” Before a tearful goodbye, we traded addresses and promised to be friends for life.I’ve kept a green notebook filled with the names of American towns, along with a love letter, a dried carnation and a stack of black and white photographs, tokens of the magic of 1989: the Berlin Wall dismantled, the Iron Curtain coming down, the scary “us” and “them” disappearing into the finally free air. Chanting “Goodbye America, where I have never been,” a popular anthem, we were bidding farewell to America the enemy, America the myth — and anticipating the discovery of the real thing. Words like “borders” and “ideology” were no longer relevant. America and Russia seemed to be united by a common yearning for peace.The years that followed generated immense good will between our nations. As a Russian in America, I met countless people who built it: a Californian doctor who helped set up children’s heart surgery centers across post-Soviet Russia; a Bay Area filmmaker who organized the first Jewish film festival in Moscow; a Seattle captain who set up joint maritime ventures with fishermen in Russia’s far east. Russian college graduates, meanwhile, flocked to America, giving their brains and talents to everything from Hollywood films to DNA sequencing. There were a lot of marriages. A popular Russian all-female band captured the spirit in the 1990s when they implored, to electric balalaika chords, a hypothetical “American Boy” to come and whisk them away.That happened to be my route. Having married into a family of former dissidents sheltered by America, I too was a testament to the flow of people and ideas. Money flowed also. My first paid job in America back in 1998, for example, was translating for the second annual U.S.-Russian Investment Symposium, hosted by Harvard University and featuring an all-star lineup of international bankers vying for the attention of the Russian guests, among them the tycoon Boris Berezovsky and the mayor of Moscow at the time, Yuri Luzhkov.Yet somewhere along the way, the good will slowed. After expressing enthusiasm for Russia’s first post-Soviet president, Boris Yeltsin, America’s leaders found his K.G.B.-fashioned successor, Vladimir Putin, less to their taste. Mr. Putin made it clear that he didn’t care. “American hegemon,” a phrase from my Soviet childhood, began popping up in Russia’s pro-Kremlin media. In the West, Russians were no longer viewed as liberated hostages of a totalitarian regime, reformed villains from James Bond movies or emissaries of the great culture of Tolstoy and Dostoyevsky, but rather as all-cash buyers of luxurious properties in Manhattan and Miami. The enchantment between the countries and their citizens dimmed, yet shared interests and social bonds held.The annexation of Crimea in 2014 was a turning point. True, Mr. Putin had previously given vent to his aggression in Georgia and, devastatingly, in Chechnya, but it was his claiming of Ukrainian territory that gave the West its wake-up call. The sanctions that followed hit the Russian economy hard. They also supplied the Kremlin with ample means to stoke anti-American sentiment. Blaming America for the country’s troubles was a familiar, almost nostalgic narrative for Russians, more than half of whom were born in the Soviet Union. The simple tune — “NATO expansion,” “Western aggression,” “enemy at the gate”— played on repeat, keying Russians to believe that America aimed for their motherland’s destruction. The propaganda worked: By 2018, America was once more regarded as Russia’s No. 1 enemy, with Ukraine, its “puppet,” coming second.In America, things weren’t nearly as bad. But Donald Trump’s arrival on the global political stage complicated the already strained Russian-American relationship. Mr. Trump cozied up to the openly authoritarian Mr. Putin, strengthening anti-Russian sentiment that had been rising since the Kremlin’s meddling in the 2016 U.S. presidential election and rarely distinguished between Mr. Putin and the country he ruled. Economic and cultural ties began to wilt as it got harder to secure visas and funding. Still, student exchanges happened, films were screened and family visits paid, if at longer intervals.The Russian missiles that struck Ukrainian cities on Feb. 24 extinguished that flickering light. America now provides billions of dollars’ worth of weapons to be used against Russia, while Russia’s stated aim is to put an end to America’s “unfettered” global domination. The two countries, once allies in the war against Nazi Germany, are effectively fighting a proxy war. As I watch videos of Russian parents egging on their children to destroy iPhones or read about threats against a venerable Seattle bakery known for its Russian-style baked goods, I’m gripped, above all, by sadness. Our post-totalitarian dream of a peaceful, friendly future is over.Apart from wreaking physical horror, Mr. Putin’s war in Ukraine is erasing countless intangibles, among them the collective good will of the West toward Russia. In my children’s future, I see no cultural miracles akin to the one that I experienced back in 1989. This is a loss for both countries, and Russia’s will be greater if Mr. Putin continues doubling down on carnage and isolation. That future isn’t set in stone. After all, the perestroika years, when the Soviet Union embarked on wholesale reforms in the name of openness, showed that Russia is capable of change.For now, though, each explosion in Ukraine also strikes at what was good in the relationship between America and Russia. In Mr. Putin’s land, “Goodbye America,” once a tongue-in-cheek song suffused with hope, has become a darkly self-fulfilling prophecy.Anastasia Edel (@aedelwriter) is the author of “Russia: Putin’s Playground: Empire, Revolution, and the New Tsar.”The Times is committed to publishing a diversity of letters to the editor. We’d like to hear what you think about this or any of our articles. Here are some tips. 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